In an application I need 24 audio channels, output.
The verdin iMX8M Plus has two I2S ports together 24 channels.
For the SAI_2 channel i intent to use the PCM1681PWPR
For the SAI_1 channel i am thinking of using two of the PCM1681 chips and combining the SCK, LRCK and BCK.
Would it be possible, with the verdin, to work with the two i2s ports together?
Or would there be a better solution to generate 24 audio signals.
The NXP iMX8M Plus module on the Toradex Verdin board indeed supports multiple I2S (also known as SAI) ports, so using two different audio DACs with this board is possible .
Regarding the sharing of SCK, LRCK, and BCK signals between the two PCM1681 chips on the SAI_1 channel, it would be possible as long as the chips are configured in a way that they correctly interpret the signals. Note that you will also need to control the PDN (power down) and FLT (filter control) pins appropriately to set the PCM1681s in the right mode. Sharing clock signals between two devices could potentially introduce noise or other signal integrity issues. A careful layout and possibly signal conditioning might be required.
To simplify your design, it would be better to use two 12-channel DACs (like the ADAU1962A), one for each SAI channel.
Thank you for your answer.
I see your point in sharing the clock signals, an extra buffer can’t hurt good point.
Your remark on the PDN and FLT pins, i am confused. Those pins are not available at the PCM1681.
I intend to control the PCM1681 with I2C, with that i should be able to control them equally.
As SAI_1 has 8 Data lines and SAI_2 only 4 Data lines, i think that combining 4+ 2 data lines from two SAI ports for one ADAU1962A is more tricky, the clock and bck lines must be in sync to pull this off.
is there any update from your side? Any progress?
Well i tried to find a 16 channel I2S chip that is available on the market, but failed to find it.
The 12 channel that Alex suggested i think that will give me more problems than the 2x 8 channel chips solution i had in mind.
I am still in doubt what solution would give me the best result on hardware and driver side.
the help we can offer her is very limited since this is something application specifc.